The palladium-catalyzed vinylation of organic halides has been reviewed by Heck, Organic Reactions, vol. 27 (1982), beginning at page 345. Process conditions, recited at page 360, do not require the use of a solvent, although an organic amine can apparently function as a solvent. Other solvents used heretofore include acetonitrile, methanol, dimethylformamide, N-methylpyrrolidinone and hexamethyl phosphoramide.
Heck, U.S. Pat. No. 3,922,299, incorporated herein by reference, teaches that the reaction can be carried out with or without a solvent. Suggested solvents include acetonitrile, tetrahydrofuran or excess olefin.
The Heck vinylation reaction has been used to vinylate various kinds of compounds, including vinylation using vinylically-unsaturated organosilicon compounds. The preparation of polysiloxane-bridged bisbenzocyclobutene monomers has been recited by Gros, U.S. Pat. No. 4,759,874, and Schrock, U.S. Pat. No. 4,812,588, both herein incorporated by reference. Other silane-containing compounds have been synthesized by Hahn et al., U.S. Pat. No. 4,831,172, herein incorporated by reference. Similar synthesis of benzocyclobutene compounds is disclosed by Kirchhoff, U.S. Pat. No. 4,540,763, herein incorporated by reference.
Known processes for reaction between halogenated organic compounds and hydrolytically-stable, vinylically-unsaturated precursor compounds have been carried out in organic solvents.
It has surprisingly been found that the Heck-type vinylation reaction can be carried out in aqueous media, including aqueous solutions of organic solvents.
It is therefore the object of this invention to provide an improved process for vinylation of halogenated organic compounds, wherein an aqueous diluent is used.